Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Metallic Twin Grain Boundaries Embedded in MoSe2 Monolayers Grown by Molecular Beam Epitaxy
Ist Teil von
ACS nano, 2017-05, Vol.11 (5), p.5130-5139
Ort / Verlag
American Chemical Society
Erscheinungsjahr
2017
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
Twin grain boundaries in MoSe2 are metallic and undergo a metal to insulator Peierls transition at low temperature. Growth of MoSe2 by molecular beam epitaxy results in the spontaneous formation of a high density of these twin grain boundaries, likely as a mechanism to incorporate Se deficiency in the film. Using scanning tunneling microscopy, we study the grain boundary network that is formed in homoepitaxially grown MoSe2 and for MoSe2 grown heteroepitaxially on MoS2 and HOPG substrates. No statistically relevant variation of the grain boundary concentration has been found for the different substrates, indicating that the grain boundary formation is substrate independent and depends mainly on the growth conditions. Twin grain boundaries exhibit three crystallographically identical orientations, and thus they form an intersecting network. Different intersection geometries are identified that imply varying defect configurations. These intersection points act as preferential nucleation sites for vapor-deposited metal atoms, which we demonstrate on the example of selective gold cluster formation at grain boundary intersections. Scanning tunneling spectroscopy shows a band gap narrowing of MoSe2 in the immediate vicinity of the metallic grain boundary, which may be associated with lattice strain induced at the grain boundary. Tunneling noise spectra taken over the grain boundaries indicate random telegraphic noise, suggestive of pinning/depinning behavior of conductive channels in the metallic grain boundaries or their intersection points. Finally, indications for incommensurate and commensurate Peierls-driven charge density wave formation were observed in microprobe transport measurements at 205 and 227 K, respectively.
Sprache
Englisch
Identifikatoren
ISSN: 1936-0851
eISSN: 1936-086X
DOI: 10.1021/acsnano.7b02172
Titel-ID: cdi_proquest_miscellaneous_1893547353
Format
–
Weiterführende Literatur
Empfehlungen zum selben Thema automatisch vorgeschlagen von bX